In-mold label system plastic container

ABSTRACT

The main object is to provide an inmold labeled type plastic container which can be fabricated, even if there are some dimensional errors in the inmold label, with no damage to aesthetic design or no drop in yield is to be provided, and further an inmold labeled type plastic container which allows the consumer to drink or eat the content safely even if he or she brings his or her mouth into direct touch with the opening is to be provided. A bottom rim is disposed in the lower part of the inmold labeled type plastic container, with its dimension being not less than 0.3 mm but not more than 20 mm, and the inmold labeled type plastic container to be provided is labeled on its bottom rim in a similar way to the side part of the container.

TECHNICAL FIELD

The present invention relates to an inmold labeled type plasticcontainer.

BACKGROUND ART

There are a variety of methods of labeling a side part of a plasticcontainer including one by which the rear face of a label is glued andthe label is stuck to the plastic container and another by which a sealtype label to whose rear face an adhesive is already applied is stuck.

Among others, the inmold labeling system by which a label is inserted atthe same time as molding of a plastic container to form the containerand the label integrally has come to be frequently used in recent years.Since a plastic container formed by this inmold labeling system usesneither glue nor adhesive and accordingly its label and resin aremelt-joined, the label does not come off even in a state of hightemperature and high humidity. Therefore, such plastic containers are invery high demand for use in humid places such as bathrooms and toiletsand as containers whose contents are to be used together with water,such as shampoo and detergent.

Furthermore, a container of the inmold labeling type, because of theabsence of a level gap between the label and the container, can bedesigned to manifest aesthetic excellence as a whole, and many of thistype are used as plastic containers for beverages and foods includingjuice, coffee and yoghurt.

DISCLOSURE OF THE INVENTION

However, where such an in mold labeling system was used, there arose aproblem that the inmold label fitted within the female mold was shovedby molten resin, when it was extruded, to give rise to wrinkles ormolten resin flowed into the gap between the female mold and the inmoldlabel.

Such problems can be solved to some extent by eliminating dimensionalfluctuations of the inmold label and fix to the inside of the femalemold by some devices or other, but it is all but impossible to eliminateerrors in every dimension of inmold labels which are mass-produced, andthe installation of a label fixing device inside the female mold wouldcomplicate the fitting of the label in itself and invite a drop inyield, which is undesirable.

Incidentally, inmold labeled type plastic containers have aestheticexcellence (more specifically, this refers to characteristics that thewhole container can be covered with a level, there is no level gapbetween the label and the plastic, and the label can be printed bygravure or offset process and accordingly can well represent the design)as mentioned above, and the inmold label can be given such functions aslight interception and barriering, with the result that they are oftenused as cups for food, especially as beverage cups, and generalconsumers often would directly bring their mouths into touch with theopenings of inmold labeled type plastic containers to drink or eat thecontents.

Therefore, the opening of an inmold labeled type plastic container isrequired to be agreeable and safe to touch.

The main object of the present invention, attempted in view of thesecircumstances, is to provide an inmold labeled type plastic containerwhich, even if there are slight dimensional errors in the inmold label,can be manufactured unaffected in aesthetic design or yield, and furtherto provide an inmold labeled type plastic container which allows theconsumer to drink or eat the content even if he or she brings his or hermouth into direct touch with the opening.

In order to solve the problems noted above, the invention provides, asstated in claim 1, an inmold labeled type plastic container fabricatedby an inmold labeling type fabricating method by which molding of thecontainer and labeling are accomplished at the same time by fitting aninmold label into a gap formed, where a female-metal mold and a malemetal mold are used, by joining the female mold and male mold andinjecting molten resin into the gap, the inmold labeled type plasticcontainer being characterized in that a flange part is formed at theupper end of the side part of the container and with dimensions of 2 mmor more in flange width and 0.5 mm or more in flange thickness.

According to this invention, since the flange width of the flange partis 2 mm or more, it is made possible to make the seal sufficientlystrong when the lid member to be stuck to the opening in the upper partof the container is to be sealed, and the user will feel nothing awkwardeven if he or she directly touches it with his or her own mouth. Also,as the flange thickness is not less than 0.5 mm, the flange part isenabled to bear the damage it is subjected to when the lid member is tobe stuck.

Further, in order to solve the problems noted above, the inventionprovides, as stated in claim 2, an inmold labeled type plastic containerfabricated by an inmold labeling type fabricating method by whichmolding of the container and labeling are accomplished at the same timeby fitting an inmold label into a gap formed, where a female metal moldand a male metal mold are used, by joining the female mold and male moldand injecting molten resin into the gap, the inmold labeled type plasticcontainer being characterized in that a bottom rim is formed in thebottom part of the container, with a dimension of not less than 0.3 mmbut not more than 20 mm, and the bottom rim is labeled in a similar wayto the side part of the container.

According to this invention, since the bottom rim with a dimension ofnot less than 0.3 mm but not more than 20 mm is formed in the bottompart of the container and is labeled in a similar way to the side partof the container, when molten resin is injected from the partconstituting the bottom of the container, the molten resin flowing fromthe bottom part to the side part flows not only toward the side part butalso toward the bottom rim part, and is therefore prevented from beingpeeled off or flowing over the front surface of the label (between theinner surface of the female mold and the label).

Even if there is any error in the inmold label, as the containeraccording to the invention has the bottom rim, the bottom rim performsthe role of an “escape” to adjust the dimensional error, with the resultthat the container is unaffected in aesthetic design.

Further, the invention provides, as stated in claim 3, an inmold labeledtype plastic container fabricated by an inmold labeling type fabricatingmethod by which molding of the container and labeling are accomplishedat the same time by fitting an inmold label into a gap formed, where afemale metal mold and a male metal mold are used, by joining the femalemold and male mold and injecting molten resin into the gap, the inmoldlabeled type plastic container being characterized in that a flange partis formed at the upper end of the side part of the container, withdimensions of 2 mm or more in flange width and 0.5 mm or more in flangethickness, a bottom rim is formed in the bottom part of the container,with a dimension of not less than 0.3 mm but not more than 20 mm, andthe bottom rim is labeled in a similar way to the side part of thecontainer.

This invention can exert the actions and effects stated in claims 1 and2 at the same time.

In the inmold labeled type plastic container stated in claim 2 or claim3, as stated in claim 4, the relationships among the wall thickness (A)of the intersection between the bottom rim and the side part of thecontainer, the wall thickness (B) of the side part of the container andthe wall thickness (C) of the side part of the container may be A≦2×Band A≦2×C.

This invention can provide an inmold labeled type plastic containerwhich, when molten resin is injected, is free from peeling of the labelduring injection molding and floating of the label after the injectionmolding, and excels in aesthetic design.

The inmold labeled type plastic container stated in any of claim 1through claim 3 may be fabricated, as stated in claim 5, by using thefemale metal mold and the male metal mold which are a female metal moldand a male metal mold joined at the flange part in the formed container,and so designed that the flange width of a flange part formed by thefemale mold is smaller than the flange width of a flange part formed bythe male mold.

When an inmold labeled type plastic container is to be formed by using afemale metal mold and a male metal mold, a deviation may arise inassembling the metal molds (even if there is not deviation between themetal molds at the beginning, the metal molds become worn and may giverise to a deviation during the production of containers); if moltenresin is injected to form a container in the presence of a deviationbetween metal molds, a level gap will occur in the deviated part, notonly marring the aesthetic design but also causing the user to feel anawkward mouth touch when drinking from the container.

However, according to this invention, since fabrication uses the femalemetal mold and the male metal mold which are joined at the flange partin the formed container and so designed that the flange width of theflange part formed by the female mold is smaller than the flange widthof the flange part formed by the male mold, even if the male mold andthe female mold deviate from each other, the deviation can be concealedby the side part on the back of the flange (the face reverse to the faceto which the lid member is to be stuck), with the result that neitherthe overall aesthetic design be marred nor the user is caused to feel anawkward mouth touch.

In the inmold labeled type plastic container stated in any of claim 1through claim 3, the thickness of the label may be, as stated in claim6, kept not to exceed 150 82 m.

When the thickness of the label increases, the width of the gap in whichinjected molten resin flows significantly differs between where thelabel is present and where it is absent, and this would inevitablyinvite a difference in the flowing velocity of the molten resinaccording to the presence or absence of the label. When a substantialdifference in the flowing velocity of the molten resin occurs in thisway, there will arise differences in the time taken by the resin todifferent parts of the container, and a so-called weld will occur in theflange part of the part where an earlier arriving part of the resin anda later arriving part of the resin meet, which might invite a fataldefect of splitting of the flange when the lid member is to be sealed.

However, according to the invention, since the thickness of the label isnot more than 150 μm, there will arise no significant difference in theflowing velocity of the molten resin between where the label is presentand where it is absent, with the result the occurrence of a so-calledweld can-be prevented.

In the inmold labeled type plastic container stated in any of claim 1through claim 3, the label may be, as stated in claim 7, a label havinga configuration in which a plurality of-thin films are stacked, the thinfilm positioned on the front face and the thin film positioned on therear face consist of thin films of the same material, and further atleast a resin film layer and a barrier layer having a defined strengthor barrier layers having a defined strength are stacked between thesethin films.

Also, as stated in claim 8, the thin film positioned on the front faceand the thin film positioned on the rear face of the label may consistof biaxially oriented polypropylene resin film layers or polyethyleneresin film layers; the resin film layers having the defined strength mayconsist of biaxially oriented polyethylene terephthalate film layers,biaxially oriented polyamide film layers or biaxially orientedpolypropylene film layers; and the barrier layers may consist of metalfoil layers, vapor-deposited metal film layers or inorganicvapor-deposited oxide film layers.

By using such a label, the label can be prevented from curling when thecontainer is formed, the label can be given a barriering function and,depending on the layer configuration of the label, the container can bemade usable in a microwave oven.

Further the inmold labeled type plastic container stated in any of claim1 through claim 3, the relationship between the fluid length (L) of theinjected molten resin and the average wall thickness (t) of thecontainer may be, as stated in claim 9, L/t≦250.

According to this invention, the pressure of the molten resin issufficiently transmitted to the flange part to provide an inmold labeledtype plastic container which is highly accurate and free from unintendedunlabeling or wrinkling, and excels in aesthetic design.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustrative diagram for describing one example ofmolding method for the inmold labeled type plastic container accordingto the present invention;

FIG. 2 is a diagram for describing the inmold labeled type plasticcontainer in a mode for carrying out the invention, and morespecifically a diagram showing an enlarge section of a bottom rim 20(sign (i) in FIG. 1);

FIG. 3 is a diagram for describing the inmold labeled type plasticcontainer in another mode for carrying out the invention, and morespecifically a diagram showing an enlarged section of a flange part 30(sign (ii) in FIG. 1);

In FIGS. 4, (a) and (b) show front views of a label for use on the sidepart and (c) shows a front views of a label for use on the bottom part;

FIG. 5 show enlarged sectional views of the shape of a flange part inthe inmold labeled type plastic container according to the invention;

FIG. 6 shows a sectional view of the inmold labeled type plasticcontainer according to the invention where its content is to be a retortfood compatible with a microwave oven; and

FIG. 7 shows a sectional view of the inmold labeled type plasticcontainer according to the invention in the absence of a bottom rim.

BEST MODE FOR CARRYING OUT THE INVENTION

First, a molding method for inmold labeled type plastic containerscommon to all the aspects of the present invention will be described inspecific terms with reference to drawings, followed by specificdescription of characteristic parts of the invention with reference tothe drawings. Incidentally, the inmold labeled type plastic containeraccording to the invention has its major characteristic in its bottomrim and flange part, and therefore in the following description thebottom rim will be considered a first characteristic feature and theflange part a second characteristic feature of the invention.

[1] Method of Forming the Inmold Labeled Type Plastic Container

FIG. 1 is a schematic illustrative diagram for describing one example ofmolding method for the inmold labeled type plastic container accordingto the invention. Incidentally, the molding method shown in FIG. 1merely shows one typical example, but is nothing to limit the method ofmolding the inmold labeled type plastic container according to theinvention.

A molding method of an inmold labeling system for molding the inmoldlabeling type plastic container according to the invention means amethod of simultaneous labeling with the molding of a container usingfemale and male metal molds, by which an inmold label is fitted within agap resulting from the joining of the female mold and the male mold andthen molten resin is extruded into the gap, more specifically a methodsuch as the one shown in FIG. 1. Thus, it uses an metal mold forinjection molding comprising a male metal mold 1 (hereinafter sometimesreferred to as simply “male mold”), a female metal mold 2 (hereinaftersometimes referred to as simply “female mold”), a runner 3, a gateopening 4, a vacuum suction device 5 a fitted to the male mold 1, vacuumsuction devices 5 b and 5 b fitted to the female mold 2 and so forth;first, a label R1 for the side part is so fitted onto the inner wallsurface of the female mold 2 as to be tightly stuck to a positioncorresponding to the whole outer wall surface of the side part of themolded container while fixing it by vacuum suction utilizing the vacuumsuction devices 5 b and 5 b and the like, and similarly a label R2 forthe bottom part is so fitted onto the surface in a positioncorresponding to the bottom part of the male mold 1 while fixing it byvacuum suction utilizing the vacuum suction device 5 a . Then, the malemold 1 is fixed to the female mold 2; after that, molten resin 6 isinjected from the gate opening 4 with a heating cylinder (not shown)into the gap formed by the female mold 2 and the male mold 1 by way ofthe runner 3 to form a container 7 matching the shape of the gap and totightly adhere the label R1 for the side part and the label R2 for thebottom part in a molten-integrated form to all over the outer wallsurface of the body part an all over the inner bottom wall surface ofthe bottom constituting that container 7; after that the molded product,which has been hardened by cooling, is taken out, thereby enabling theinmold labeled type molded container according to the invention to beproduced.

And, first the inmold labeled type plastic container 7 according to theinvention formed by this method is characterized in that therelationship between the fluid length L of the injected molten resin andthe average wall thickness 5 (not shown) of the container 7 is L/t≦250.

By keeping the fluid length L of the molten resin 6 and the average wallthickness 5 of the container 7 in such a relationship, the pressure ofthe molten resin is sufficiently transmitted to the flange part toobtain an inmold labeled type plastic container which is highly accurateand free from unintended unlabeling or wrinkling, and excels inaesthetic design.

[2] First Characteristic Feature of the Inmold Labeled Type PlasticContainer

FIG. 2 is a diagram for describing the inmold labeled type plasticcontainer 7 in a mode for carrying out the invention formed by theinmold labeled type plastic container molding method shown in FIG. 1,and more specifically a diagram showing an enlarge section of a bottomrim 20 (sign (i) in FIG. 1).

As shown in FIG. 2, the bottom rim 20 is formed in the lower part of theinmold labeled type plastic container 7 according to the invention and,with its dimension x being not less than 0.3 mm but not more than 20 mm,the bottom rim too is characterized by being labeled with a label R1similar to that on the-container's side part 8.

Setting the dimension x of the bottom rim 20 not less than 0.3 mm butnot more than 20 mm and labeling it with the label R1 similar to that onthe container's side part 8 as in the present invention causes themolten resin to be fluid as indicated by arrow 100 in the diagramprevents the molten resin from flowing over the surface of the label R1.

The reason is that, if the dimension x of the bottom rim 20 is shorterthan 0.3 mm (the bottom rim 20 is absent), the tip portion of the labelR1 will be positioned in the vicinity of the joint portion between thecontainer's side part 8 and the container's bottom part 9, the moltenresin will flow over the surface of the label R1 at the time of moldingand adversely affect the aesthetic design of the container 7. On theother hand, if the dimension x of the bottom rim 20 is longer than 20mm, there will be no problem in its relationship to the label R1, buteventually the wall thickness (a) of the intersection between the bottomrim 20 and the container's bottom part 9 will increase, sometimes givingrise to a problem, such as the label coming off in the container afterinjection molding.

The inmold labeled type plastic container 7 according to the inventionis also characterized by relationships of A≦2×B and A≦2×C among the wallthickness (a) of the intersection between the bottom rim 20 and thecontainer's bottom part 9, the wall thickness (b) of the container'sbottom part and the wall thickness (c) of the container's side part.

By keeping the above-stated relations among these wall thicknesses, theflow of the molten resin can be smoothened, with the result that thelabels R1 and R2 from coming or floating.

It is preferable for the wall thickness (a) of the intersection to be ina range of 1.0 to 3.0 mm, and 1.5 mm is particularly preferable in thisrange. It is preferable for the wall thickness (b) of the container'sbottom part to be in a range of 0.5 to 1.5 mm, and 1.0 mm isparticularly preferable in this range. Further, it is preferable for thewall thickness (c) of the container's side part to be in a range of 0.5to 1.5 mm, and 0.7 mm is particularly preferable in this range.

[3] Second Characteristic Feature of the Inmold Labeled Type PlasticContainer

FIG. 3 is a diagram for describing the inmold labeled type plasticcontainer 7 in another mode for carrying out the invention formed by theinmold labeled type plastic container molding method shown in FIG. 1,and more specifically a diagram showing an enlarge section of a flangepart 30 (sign (ii) in FIG. 1).

As shown in FIG. 3, the inmold labeled type plastic container 7according to the invention has the flange part 30 formed at the upperend of its side part 8, and is characterized by its dimensions which arenot less than 2 mm in flange width y and not less than 0.5 mm in flangethickness z.

By setting the flange-width y of the flange part 30 to not less than 2mm as in the present invention, it is made possible to make the sealsufficiently strong when the lid member to be stuck to the opening partof the container 7 is to be sealed, and the user will feel nothingawkward even if he or she directly touches it with his or her own mouth.According to the invention, no particular upper limit is prescribed tothe flange width y of the flange part 30, and the width can be set asdesired. However, considering the case in which the user directly drinksor eats the content with his or her mouth in direct contact with thecontainer 7, too great a width would not be preferable;.in specificterms about 2.0 mm is preferable, and a width greater than 10.0 mm wouldpose an obstacle and therefore be undesirable when the content is to bedrunk or eaten.

Also, by setting the flange thickness z to not less than 0.5 mm as inthe invention, the flange part is enabled to bear the damage it issubjected to when the-lid member is to be sealed. The inventionprescribes no particular upper limit to this flange thickness z either,and the thickness can be set as desired. However, considering the casein which the user directly drinks or eats the content with his or hermouth in direct contact with the container 7, too great a thicknesswould conceivably make him or her feel awkward, and therefore about 1.0mm is preferable.

Further, the inmold labeling type plastic container 7 according to theinvention is characterized in that the female mold 2 and the male mold 1are joined at the flange part 30 in the formed container 7 (seereference sign 31 in FIG. 3), and the container is fabricated by usingthe female mold 2 and the male mold 1 so designed that the flange widthy′ of a flange part 32 formed by the female mold 1 is smaller than theflange width y of a flange part 33 formed by the male mold 1.

The use in this way of the female mold 2 and the male mold 1 so designedthat the flange width y′ of the flange part 32 formed by the female mold1 is smaller than the flange width y of the flange part 33 formed by themale mold 1 results in the formation of the lower side of the flangeshown in FIG. 3 (reference 'sign 32) in a smaller size, even if anydeviation, either back and forth or right and left, arises between thefemale mold 1 and the male mold 2, the lower side 32 of the flange willnot protrude, with the result that the overall aesthetic design of thecontainer 7 is not adversely affected.

In this case, though the metal molds will be so designed as to create anintentionally disposed level gap S on the flange part 30 as shown inFIG. 3, the lower side 32 of the flange is invisible when viewed fromabove the container, and accordingly no problem will arise; the user islikely to have no awkward feeling even when his or her mouth is broughtinto direct touch with the flange.

The dimension of the level gap S intentionally disposed to tolerate thedeviation arising when the metal molds are combined, if it issubstantially equal to the deviation arising when the metal molds arecombined, can be set as desired according to the accuracy of theformation apparatus that is actually used. If it is a usual formationapparatus for inmold labeled type plastic containers, the dimension of Swill be sufficient if it is set to about 0.05 mm.

Further at the reference 31 of the flange part 30 of the container 7according to the invention, its tip 34 may as well be rounded asillustrated because the female mold 2 and the male mold l are combined.

[4] Other Characteristic Features

Other characteristic features of the inmold labeling type plasticcontainer according to (various modes for carrying out) the presentinvention will be described in specific terms.

(Molten Resin)

First, as the molten resin 6 for use in molding the container 7according to the invention as described above, one of variouspolyethylene resins for molding use such as high density polyethylene,medium density polyethylene, low density polyethylene or some otherkind, polypropylene, polystyrene, polyethylene terephthalate,polycarbonate or the like can be used.

(Labels)

On the other hand, for the label R1 for the side part and the label R2for the bottom part for use in molding the inmold labeled type plasticcontainer 7 according to the invention as described above, there is noparticular restriction if the thickness is not greater than 150 μm, anyof all the already known in mold label shaving various functions can beused for the purpose.

However, it is preferable to use as labels for the inmold labeled typeplastic container according to the invention labels each having aconfiguration in which a plurality of thin films are stacked, the thinfilm positioned on the front face and the thin film positioned on therear face consist of thin films of the same material, and further atleast a resin film layer and a barrier layer having the defined strengthor barrier layers having the defined strength are stacked between thesethin films; it is further preferable that the thin film positioned onthe front face and the thin film positioned on the rear face of thelabel consist of biaxially oriented polypropylene resin film layers orpolyethylene resin film layers, the resin film layers having the definedstrength consist of biaxially oriented polyethylene terephthalate filmlayers, biaxially oriented polyamide film layers or biaxially orientedpolypropylene film layers, and the barrier layers consist of metal foillayers, vapor-deposited metal film layers or inorganic vapor-depositedoxide film layers.

As materials to constitute the thin films positioned on the front faceand the rear face of the label, for instance one of various polyethyleneresins for molding use such as high density polyethylene, medium densitypolyethylene, low density polyethylene, linear (straight chain)polyethylene or some other kind, polypropylene resins, polyester resins,polyamide resins or some other resin films or sheets. Among theaforementioned polyethylene resins, co-extruded films or sheets of theseresins can also be used. As films or sheets of the aforementionedresins, unoriented or oriented films oriented in the monoaxial orbiaxial direction can be used, and their desirable thickness is about 6to 100 μm, more preferably about 12 to 50 μm. By configuring in this waythe thin film positioned on the front face and the thin film positionedon the rear face of the label consist of thin films of the samematerial, the fabricated label can be prevented from curling. Further,it is desirable to use as the material to constitute the thin filmpositioned on the rear face of the label a heat-sealable material whichhas a property, when the polyethylene resin for molding use constitutingthe container is injected and extruded to come into contact with it, tomelt together and tightly adhere to each other; it is desirable to useas the material to constitute the thin film positioned on the front faceof the label a material which can keep the resilience, strength andother characteristics of the label, more desirably what has a rigidityof 5.000 Kg/cm2 in Young's modulus.

Next, as materials for the resin film layers having the defined strengthto constitute part of the label according to the invention, for instancepolyester resin (polyethylene terephthalate resin), polyamide resin,polyaramid resin, polypropylene resin, polycarbonate resin, polyaracetalresin or some other tough resin films or sheets can be used. And film orsheet of any of the resins stated above performs a function of furtherreinforcing the function of the material constituting the aforementionedoutermost layer, and preferably should have, for instance, rigidity andbe excellent in mechanical, physical, chemical and other properties. Itis preferable to use as the aforementioned resin films or sheetsoriented films oriented in biaxial directions. Further according to theinvention, the thickness of the resin films or sheets need not begreater than the minimum required to provide them with sufficientstrength, rigidity and other properties; too great a thickness wouldentail a disadvantage of boosting the label cost or, conversely, toosmall a thickness would entail poor strength, rigidity and otherproperties and therefore be undesirable. According to the presentinvention, it is preferable for the reasons stated above to use athickness of about 10 μm to 50 μm, most desirably about 12 μm to 25 μm.

Then, as materials for the barriering base layer to constitute part ofthe label, a material having a property to intercept light includingsunlight or a material having a property not to allow permeation ofwater vapor, water, gas or the like can be used, and this may be asingle-component base material, a composite base material combining twoor more kinds of base materials, or the like. More specifically, whatcan be used may be, for instance, an aluminum foil havinglight-intercepting and barriering properties or a resin film on whichsuch a foil is vapor-deposited, a resin film having a vapor-depositedfilm of an inorganic oxide such as silicon oxide having a barrieringproperty or aluminum oxide, a resin film or sheet of low densitypolyethylene, medium density polyethylene, high density polyethylene,straight chain low density polyethylene, polypropylene,ethylene-propylene copolymer or the like, a resin film or sheet having agas-barriering property of polyester resin, polycarbonate resin, nylonresin (polyamide resin), acryl nitrile resin, polyvinyl alcohol,saponified ethylene-acetic vinyl copolymer or the like, or a film orsheet of one or another of various colored resins, which have a propertyto intercept light, formed by adding a coloring agent such as a pigmentaugmented with a desired additive or the like to the resin, and mixingand kneading them into a film. Any one of these materials singly or incombination with another or more can be used. Any of the aforementionedresin films or sheets may have any desired thickness, but it is usuallyabout 6 μm to 100 μm, and more preferably about 7 μm to 30 μm. Furtherin the foregoing, an aluminum foil of about 6 μm to 50 μm in thicknessor a resin film on which an aluminum foil is vapor-deposited of about100 Å to 1000 Å in thickness can be used. As a resin film to support theaforementioned vapor-deposited film, for instance a polyester film,polyamide film, polyolefin film, polycarbonate film, polyvinyl alcoholfilm, saponified ethylene-acetic vinyl copolymer film or some other filmcan be used.

Incidentally, since a label is usually placed under severe conditionsboth physically and chemically, the laminated materials to constitutethe label are subject to stringent requirements regarding strengthagainst deformation, strength against drop impact, resistance to pinholes, thermal resistance, sealing performance, qualitative stability,working ease, sanitariness and in other respects, and for this reasonother materials satisfying these conditions can be used as desiredbesides the materials enumerated above; they can be selected from thefilms or sheets of, for instance, low density polyethylene, mediumdensity polyethylene, high density polyethylene, linear low densitypolyethylene, polypropylene, ethylene-propylene copolymer,ethylene-acetic vinyl copolymer, monomer resin, ethylene-ethyl acrylatecopolymer, ethylene-acrylic acid copolymer or methacrylic acidcopolymer, methyl pentene polymer, polybutene resin, vinyl polychlorideresin, vinyl polyacetate resin, polyvinylidene chloride resin, vinylchloride-vinylidene chloride copolymer, poly(meta)acryl resin, polyacrylnitrile resin, polystyrene resin, acrylonitrile-styrene copolymer (ASresin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyesterresin, polyamide resin, polycarbonate resin, polyvinyl alcohol resin,saponified ethylene-acetic vinyl copolymer, fluorine resin, diene resin,polyaracetal resin, polyurethane resin, nitrocellulose and other knownresins. Besides them, for instance films such as cellophane or syntheticpaper or the like can also be used. In the present invention, theaforementioned resin films or sheets can be used unoriented or orientedin uniaxial or biaxial directions. Their thickness can be selected asdesired from a range of about a few μm to 150 μm and used. Furtheraccording to the invention, the resin films or sheets may be in anystate, such as extruded film, inflation film or coating film.

Next to describe the fabrication method for the above-mentionedlaminated materials to be stacked to fabricate a label according to theinvention, applicable methods include one or another of laminatingmethods for use in fabricating a usual wrapping material including, forinstance, the extrusive laminate method, sand laminate method,co-extrusion laminate method, dry laminate method, solvent-free drylamination method or some other method. And in performing theabove-described lamination according to the invention, for instance,pretreatment such as corona treatment, ozone treatment or frametreatment can be applied to-the film and, for example, one or another ofisocyanate (urethane), polyethylene imine, polybutadiene, organictitanium and other anchor coating agents, or one or another of knownanchor coating agents, adhesives and the like including polyurethane,polyacryl, polyester, epoxy, vinyl polyacetate, cellulose or some otheradhesive for use with laminates can be used.

Incidentally, in any of the above-mentioned fabrication methods forlaminated materials to be stacked to fabricate a label according to theinvention, as an adhesive extrusion resin to constitute the adhesivelayer in performing extrusion lamination, for instance any ofpolyethylene, ethylene-(-ethyl acrylate copolymer, polypropylene,polybutene, polyisobutene, polyisobutylene, polybutadiene, polyisoprene,ethylene-methacrylic acid copolymer, copolymers of ethylene andunsaturated carbonic acid such as ethylene-acrylic acid copolymer oracid-denatured polyolefin resin obtained by denaturing one or another ofthem, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylatecopolymer, ionomer resin, ethylene-vinyl acetate copolymer or the likecan be used. Further, as the adhesive to constitute the adhesive layerfor dry lamination according to the invention, in specific terms atwo-part hardening type urethane adhesive used in dry lamination or thelike, polyester urethane adhesive, polyether urethane adhesive, acryladhesive, polyester adhesive, polyamide adhesive, vinyl polyacetateadhesive, epoxy adhesive, rubber adhesive or some other adhesive can beused.

Next will be described the shape of the label for use in the inmoldlabeled-type plastic container according to the invention.

FIGS. 4(a) and (b) show front views of the label R1 for the side partand FIG. 4(c), a front view of the label R2 for the bottom part.

As shown in FIG. 4(a), the label R1 for the side part is in a fan shape,and cuts 42 and 42 may be formed in lower parts of two side edges 41 and41 of the label R1 for the side part. These cuts 42 and 42, at theirmaximum length, extend to the parts of the side part 8 (see FIG. 1)matching the bottom rim 20, and as a result the height h of the cuts 42and 42 also is substantially equal to the distance from the bottom endof the label R1 for the side part to the top end of the bottom rim 20.

By providing the label R1 for the side part with the cuts 42 and 42 inthis way, when the label R1 for the side part is fitted into the femalemetal mold 2, the lower parts of the two side edges 41 and 41 of thelabel R1 for the side part are prevented from coming into contact withthe protruding portion 2 a of the female metal mold 2 (see FIG. 1),which would peel off the lower part-of this label R1 for the side part.For this reason, there is no possibility for the injected resin 6 to becaused to flow outside the label R1 for the side part by the peeling-offof the label R1 for the side part, and instead the label R1 for the sidepart can be arranged in its due position outside the side part 8.

On the other hand, the label R1 for the side part is in a fan shape asshown in FIG. 4(b), and its four corners may form curved cuts. In thiscase, the cuts 42 need not be formed. The reason is that, by forming thefour corners of the label R1 for the side part in a curved form, even ifit comes into contact with the protruding portion 2 a of the metal mold2 (see FIG. 1), the label R1 will slide and reach its regular position.

Also, as shown in FIG. 2, the diameter of the label R2 for the bottompart may be smaller than the outer diameter D of the side part 8 on theplane of arrangement of the label R2 for the bottom part and greaterthan the outer diameter E of the bottom part 9 on the plane ofarrangement of the label R2 for the bottom part. Thus, a relationship ofE<the diameter of the label R2 for the bottom part □ D can be adopted.Further, it is preferable for the periphery 43 (see FIG. 4(c)) of thelabel R2 for the bottom part to protrude outward from the bottom part 9and to descend.

By setting the diameter of the label R2 for the bottom part larger thanthe outer diameter E of the bottom part 9 in this way, when the label R2for the bottom part is fitted into the female metal mold 2 (see FIG. 1),even if the label R2 for the bottom part somewhat deviates, the bottompart 9 of the container 7 can be sufficiently covered by the label R2.As a result, the gas,barriering and other functions of the bottom part 9can be enhanced. Also, by setting the diameter of the label R2 for thebottom part smaller than the outer diameter D of the side part 9, theinjected resin 6 can be let smoothly flow around the bottom rim 20.

Also, in the inmold labeling type plastic container 7 according to theinvention shown in FIGS. 1 through 3 for instance, the label R2 for thebottom part need not be used in every case, and its use can be dispensedwith where it is unnecessary (for instance-where the container's bottompart requires no aesthetic design or the container's bottom part needsno gas barriering).

(Lid Member)

One or another of various known materials can be used as the material ofthe lid member for sealing the inmold labeling system type plasticcontainer according to the invention. More specifically, any film orsheet of polyester resin, polyamide resin, polyaramid resin,polypropylene resin, polycarbonate resin, polyaracetal resin, fluorineresin or some other tough resin, or of various paper base materials canbe used. As films or sheets of the aforementioned resins, unoriented ororiented films oriented in the uniaxial or biaxial direction can beused. Also, like the aforementioned inmold labels R1 and R2, the lidmember can be formed in a laminated structure. For instance, where thelid member is to be provided with a property to intercept lightincluding sunlight or a material having a property not to allowpermeation of water vapor, water, gas or the like, materials having suchproperties can be stacked; what can be used maybe, for instance, analuminum foil having light-intercepting and barriering properties or aresin film on which such a foil is vapor-deposited, a resin film with abarriering property having a vapor-deposited film of an inorganic oxidesuch as silicon oxide or aluminum oxide, a resin film or sheet of lowdensity polyethylene, medium density polyethylene, high densitypolyethylene, straight chain low density polyethylene, polypropylene,ethylene-propylene copolymer or the like, a resin film or sheet having agas-barriering property of polyester resin, polycarbonate resin, nylonresin (polyamide resin), acryl nitrile resin, polyvinyl alcohol,saponified ethylene-acetic vinyl copolymer or the like, or a film orsheet of one or another of various colored resins having a barrieringproperty such as water formed by adding a coloring agent such as apigment augmented with a desired additive or the like to the resin andmixing and kneading them into a film.

The foregoing description refers to only one mode for implementing theinmold labeled type plastic container according to the invention, andtherefore the invention is not limited by the foregoing description, butcan be adapted to various purposes according to the way in which thecontainer is to be used.

(For Microwave Oven (Retort Food) Use)

The inmold labeled type plastic container according to the invention canbe suitably used as a container applicable to microwave ovens, and inthis case the flange part can as well be shaped not only as shown inFIG. 3 but also as shown in FIGS. 5(a) and (b).

As shown in FIG. 5(a), a seal protruding part 50 is disposed on theupper face of the flange part 30 and a reinforcing protruding part 51hanging from the outer tip of the flange part 30 may also be provided.Incidentally, the seal protruding part 50 need not be provided in somecases. Also, as shown in FIG. 4(b), the flange part 30 may be inclineddownward at a fixed angle α° to a horizontal line 52, which is anextension of a horizontal line linking the opening of the container andindicated by a dotted line. It is preferable for this fixed angle α tobe about 1° to 10° and more preferably 2° to 5°. Such a flange partfacilitates the opening and closing of the container, and therefore issuitable for a container whose content is to be a retort food compatiblewith a microwave oven.

FIG. 6 shows a sectional view of the inmold labeled type plasticcontainer according to the invention where its content is to be a retortfood compatible with a microwave oven.

As shown in FIG. 6, a container body 60 comprises a circumferential sidewall part 61 constituting the barrel of the container, a flange part 62continuous outward from the top end of the circumferential side wallpart 61, a bottom wall part 63 continuous laterally from the bottom endof the circumferential side wall part 61, and a bottom rim 64 continuousin the perpendicular direction from the bottom end part of thecircumferential side wall part. 61. Incidentally, the flange part 62 hasa configuration in which the flange part 62 constituting the containerbody 60 is inclined downward from the horizontal line indicated bydotted line L from the top end of the circumferential side wall part 61and is continuous outward as shown in FIG. 5.

In such an inmold labeled type plastic container 60 for retort food use,an annular stacking rib. 65 can be disposed on the inner circumferentialface of the circumferential side wall part 61 constituting the containerbody 60. And according to the invention, by disposing the annularstacking rib 65 as stated above, it is made possible to stack suchcontainers 60 and provides a reinforcing effect to increase the strengthof its barrel. A container to contain a retort food and to be applied toa microwave oven requires a certain strength (namely it has to bearretorting or boiling); further with a view to ensuring a sufficient dropstrength and other properties required of the container, regarding thewall thicknesses of the circumferential side wall part 61, the flangepart 62 and the bottom wall part 63 constituting the container body 60,it should desirably be such a container injection molded with adjustmentto keep the wall thickness T1 of the circumferential side wall part 61in a range of 0.6 to 1.2 mm, the wall thickness T2 of the bottom wallpart 3, 0.7 to 1.3 mm, and the wall thickness T3 of the flange part 62,0.9 to 1.5 mm.

(What Has No Bottom Rim)

Although a bottom rim (30 or 64) is formed in every one the inmoldlabeled type plastic containers described above, the bottom rim is notnecessarily indispensable, but a form shown in FIG. 7 is alsoacceptable.

An inmold labeled type plastic container 70 shown in FIG. 7 comprises aflange part 71, a side wall part 72 hanging from the flange part 71 anda bottom part 73 continuous to the side wall part 72. Further the outerbottom face of the bottom part 73 constitutes a grounding face. Further,an annular stacking rib 74 erecting from the bottom part 73 of thecontainer is disposed on the inner circumferential face of the side wallpart 72. To describe in further detail the configuration of the cornerparts of the container bottom with respect to the above-described inmoldlabeled type plastic container 70 according to the invention, thethickness of the side wall part 72 in the vicinity of the upper part ofthe annular stacking rib 74 being represented by U1, the thickness ofthe side wall part 72 between the bottom part 73 and the-annularstacking rib 74 being represented by U2 and further the thickness of thebottom part 73 being represented by U3, it is preferable that they havea relationship of U3>U2>U1. Further in the most desirable mode of theinvention, it is preferable for them to have relationships of U3=U1+0.4mm and U2=U1+0.2 mm. In the container 70, regarding the configuration ofthe corner parts of the container bottom, it is preferable for the curveof the inner face P1 of the intersection between the bottom part 73 andthe side wall part 72 to have its radius r1 in a range of 1.5 U1 to 3 U1and the curve of the outer face P2 of the intersection between thebottom part 73 and the side wall part 72 to have its radius r2 in arange of 1/2 U3 to 1/4 U3. Further, in more specific terms, in the mostdesirable mode of the invention, it is preferable for the curve of theinner face P1 to have its radius r1 in a range around 2.0 U1, from 1.7U1 to 2.3 U1 and the curve of the outer face P2 to have its radius r2 ina range around 1/3 U3. In the foregoing, U1, U2 and U3 are in mm units.

In the foregoing, by adjusting the thickness U1 of the side wall part 72in the vicinity of the upper part of the annular stacking rib 74, thethickness U2 of the side wall part 72 between the bottom part 73 and theannular stacking rib 74, and the thickness U3 of the bottom part 73 asdescribed above, namely by increasing the thickness of the side wallpart 72 toward the bottom and giving a greater thickness to the bottompart than the thickness of the side wall part, the drop strength of theinmold labeled type plastic container according to the invention isincreased. Further by adjusting the radius r1 of the curve of the innerface P1 of the intersection between the bottom part 73 and the side wallpart 72 and the radius r2 of the curve of the outer face P2 of theintersection between the bottom part 73 and the side wall part 72,namely by making curvilinear the inner face P1 of the intersectionbetween the bottom part 73 and the side wall part 72 and the outer faceP2 of the intersection between the bottom part 73 and the sidewall part72 and keeping smaller the radius r1 of the curve of the inner face P1of the intersection between the bottom part 73 and the side wall part 72to increase the thickness of the inner face P1 part, together with theadjustment of the thickness U1 of the side wall part 72 in the vicinityof the upper part of the annular stacking rib 74, the thickness U2 ofthe side wall part 72 between the bottom part 73 and the annularstacking rib 74 and the thickness U3 of the bottom part 73, the dropstrength of the inmold labeled type plastic container according to theinvention is further enhanced. In the foregoing, if the radius r1 of thecurve of the inner face P1 of the intersection between the bottom part73 and the side wall part 72 surpasses 3 U1, dents in the molded resinof the bottom part will become too great, which is undesirable; or if itis less than 1.5 U1, it will become difficult to keep its strength,which also is undesirable. Further in the foregoing, if the radius r2 ofthe curve of the outer face P2 of the intersection between the bottompart 73 and the side wall part 72 is less than 1/4 U3, the bottom partof the container will become close to an angular face to the curve,which could trigger cracking when the container is dropped and would beundesirable. Or if it surpasses 1/2 U3, it will become easier for themolded resin to flow toward the outer face of the label at the time ofinjection molding, and this again is undesirable. In the foregoing, r1and r2 are in mm units.

To add, it is preferable to use the aforementioned laminated label asthe label in this case, and the preferable position-in which the labelR1 is to be disposed is a gap configured as a gap X in a range of0<X<1/2 U3 between the bottom face constituting the grounding face ofthe bottom part 73 of the container and the bottom end of the label R2disposed on the outer wall face of the side wall part 72 as shown inFIG. 7; in more specific terms, the most desirable form is around X=1/3U3. In the foregoing, if X surpasses 0, namely if the label becomeslonger that the bottom face of the bottom part, the label will be rolledonto that bottom face from the bottom part and tend to become wrinkled,which is not undesirable, or if X surpasses 1/2 U3, namely if the lengthof the bottom end of the label decreases, it will become easier for themolded resin to flow toward the outer face of the label at the time ofinjection molding, and this also is undesirable. In the foregoing, X isin mm units.

According to the invention so far described, an inmold labeled typeplastic container excelling in aesthetic design and whose label isprevented from being peeled off or rolling onto the surface side of thelabel (between the inner surface of the female mold and the label) canbe provided.

EXAMPLES

The present invention will be described in further detail with referenceto examples thereof.

Example 1

As the resin for the plastic container body, HDPE (M.F.R.: 40 g/10 min)was used (resin temperature: 220° C.); this resin and a label of 90 μmin thickness were integrally molded by the molding method for inmoldlabeled type plastic containers illustrated in FIG. 1 to fabricate aninmold labeled type plastic container of Embodiment 1, and it was filledwith a content.

Details of the parts of the inmold labeled type plastic container ofthis Embodiment 1 including the dimensions are as follows:

Dimension of the bottom rim: 0.9mm

Thickness of the intersection between the bottom rim and the container'sbottom part: 1.0 mm

Thickness of the container's bottom part: 1.1 mm

Thickness of the container's side part: 0.77 mm

Flange width: 4.0 mm

Flange thickness: 1.0 mm

Relationship between the fluid length (L) of the injected molten resinand the average wall thickness (t) of the container (L/t): About 175

Configuration of the label: oriented polypropylene (30 μm), adhesive,polyethylene terephthalate (printing base) (12 μm), adhesive, aluminumfoil (barrier layer) (7 μm), adhesive, polypropylene (heat seal layer)(30 μm)

Configuration of the lid member: Aluminum foil (45 μm), sealant film (30μm).

Overall height of the container: 110 mm

Capacity of the container: 300 cc

Content: Coffee-flavored milk

Volume of the content: 240 cc (the content was sterilized with a mist ofhydrogen peroxide before the container was filled with it, and theinside of the container was dried).

The inmold labeled type plastic container of Embodiment 1 was found tobe a plastic container excelling in aesthetic design, whose label isprevented from being peeled off or wrinkled. When a container similar toEmbodiment 1 by using a label whose dimensions involved more errors thanthe side part label used in Embodiment 1, a plastic container excellingin aesthetic design, whose label was prevented from being peeled off orwrinkled, was successfully obtained.

The inmold labeled type plastic container of Embodiment 1, excelling insuitability for being filled with and packaging the content, suitabilityfor distribution, preservability and other respects, was not destroyedwhen it was dropped five times from a height of 50 cm, and foundexcelling in light interception and, moreover in respects of permeationof oxygen and permeation of humidity.

Example 2

As the injected resin material for the plastic container body,polypropylene was used and, as the label material a film formed bystacking three layers of polyethylene terephthalate film (12μm)/aluminum foil (15 μm)/polypropylene film (60 μm) was used. Thislabel material, after characters and pictures were printed on the PETfilm as the thin layer positioned on its front (outermost) side and thealuminum foil as the barrier layer was laminated by using an adhesive,was formed into a three-layered film with the polypropylene film as thethin layer positioned on its rear (innermost) side being laminated byusing an adhesive, and punched into prescribed shapes (a fan shape forthe side label and a round having a gate hole at the center for thebottom label).

Then, as shown in FIG. 1, these labels (the side label R1 and the bottomlabel R2) were arranged on the side face and the bottom face of thefemale mold 2 and, after the male mold 1 was pressed in from above, theresin 6 was injected into the cavity through the gate 4 to perform usualinjection molding of inmold labels.

Measuring the barriering performance of the molded container therebyobtained gave the values of oxygen permeability and water vaporpermeability shown in Table 1.

Since the innermost layer of this label material is the same material asthe resin of the container body, the label material and the containerbody can be integrated without using an adhesive.

To add, while using polypropylene as the injected resin material toconstitute the container body, a film of the following laminatedconfiguration of the following layers, from the outermost to theinnermost, was used as the label material in addition to the above.

(1) Stretch polypropylene film (printing base) (30 μm)/aluminum foil(barrier layer) (15 μm)/oriented polypropylene film having a heat seallayer (adhesive layer) (30 μm);

(2) Stretch polypropylene film (printing base) (30 μm)/polyethyleneterephthalate film on which silicon oxide is vapor-deposited (barrierlayer) (12 μm)/oriented polypropylene film having a heat seal layer(adhesive layer) (30 μm);

(3) Unoriented polypropylene film (30 μm)/polyethylene terephthalatefilm (printing base) (12 μm)/polyvinylidene chloride film (barrierlayer) (30 μm)/unoriented polypropylene film (adhesive layer) (30 μm);

(4) Stretch polypropylene film (30 μm)/polyethylene terephthalate film(printing base) (12 μm)/polyethylene terephthalate film on which siliconoxide is vapor-deposited (barrier layer) (12 μm) /oriented polypropylenefilm having a heat seal layer (adhesive layer) (30 μm); and

(5) Unoriented polypropylene film (30 μm)/polyethylene terephthalatefilm (printing base) (12 μm)/aluminum foil (barrier layer) (9μm)/polyethylene terephthalate film (12 μm)/unbriented polypropylenefilm (adhesive layer) (30 μm). TABLE 1 Oxygen Water vapor permeabilitypermeability Barrier layer (cc/pkg · day · atm) * (g/pkg · day) * PETwith silicon oxide 0.07 0.0041 vapor-deposited thereon Polyvinylidenechloride film 0.08 0.0043 Aluminum foil 0.06 0.00088 None 6.70 0.01* Measuring methods:For oxygen permeability 23° C. in temperature, 90% RH in humidity,purged for 3 days; MOCON's Oxtran usedFor water vapor permeability Calcium chloride weight method, measuredfor 6 days; 40° C. in temperature, 90% RH in humidity

Generally, when a label material is to be arranged on the side face andthe bottom face of the female mold 3 after it is punched into aprescribed shape, the extent of curling of the label material affectsthe yield of injection molding. Namely, the smaller the curling of thelabel material, the higher the yield.

To reduce the curling of the label material, it is desirable toconfigure the laminated structure of the label material in a symmetricalpattern centering on the central layer.

In the label material having the configuration of (1) , (2) and (5)layers, it is possible to configure the laminated structure in asymmetrical pattern centering on the central layer, and the labelmaterial of (3) and (4) can also be considered to have a symmetricallaminated structure if the polyethylene terephthalate film and thepolyethylene terephthalate film on which silicon oxide isvapor-deposited are considered a single polyethylene terephthalate film.For this reason, the curling of the label material was successfullyreduced at the time of punching. Where the label material having theconfiguration of (1) through (5) layers was used, both the gasbarriering characteristic and the tight adhesiveness to the injectedresin were satisfactory.

Example 3

A face of a biaxially oriented polypropylene film of 30 □m in thicknesswas coated with a polyurethane adhesive to a thickness of 4 g/m² (in adry state) to form an adhesive layer, and a biaxially orientedpolyethylene terephthalate film of 12 μm in thickness, on one face ofwhich a prescribed print pattern was printed to form a printed layer wasdry-laminated over a face of the adhesive layer. Next, a face of thisbiaxially oriented polyethylene terephthalate film was coated with apolyurethane adhesive to a thickness of 4 g/m² (in a dry state) in thesame way as above to form an adhesive layer, and further a biaxiallyoriented polyethylene terephthalate film on which silicon oxide of 12 μmin thickness was vapor-deposited was dry-laminated on a face of theadhesive layer. After that, the face of the biaxially orientedpolyethylene terephthalate film on which silicon oxide wasvapor-deposited was coated with a polyurethane adhesive to a thicknessof 4 g/m² (in a dry state) in the same way as above to form an adhesivelayer, and then a biaxially oriented film of 30 μm in thickness, mainlyconsisting of polypropylene and having a heat seal layer, wasdry-laminated over a face of the adhesive layer to fabricate a laminatedmaterial for label formation. By using this laminated material for labelformation, a label for the outer circumferential face to be tightlyadhered to the whole outer wall face of the circumferential side wallpart constituting an injection molded container of prescribed dimensionsand similarly a label for the bottom face (perforated label) to betightly adhered to the whole outer wall face of the bottom wall partconstituting the injection molded container were fabricated by punching.Next, the label for the outer circumferential face and the label for thebottom face fabricated as described above were so fitted to the innerwall face of the metal mold that its biaxially oriented film face havingthe heat sealing function comes into contact with the molded resin whilevacuum-sucking to fix it by utilizing a vacuum suction device or thelike. Then the male metal mold was fixed to the female metal mold; afterthat polypropylene resin melted by a heating cylinder was injected froma gate opening by way of a runner into a space formed by the femalemetal mold and the male metal mold to form a container matching theshape of the space between the metal molds; at the same time, the labelwas closely adhered to the outer wall face of the circumferential sidewall part of the barrel constituting that container and the outer wallface of the bottom wall part by melting integration, followed by coolingand hardening, and the molded product was taken out to fabricate aninmold labeled injection molded container for retort food according tothe invention (see FIG. 6). Incidentally, the capacity of the containerwas 320 cc, and the flange part constituting the injection moldedcontainer was disposed with a downward inclination of 3° to thehorizontal line of the opening. The inmold labeled injection moldedcontainer for retort food fabricated as described above was filledthrough its opening with curry roux (290 g) as the content to fill itinto a package; after that, over its opening, a biaxially orientedpolyethylene terephthalate film whose internal face consisted of anunoriented polypropylene resin film having a heat sealing function and,over which silicon oxide was further vapor-deposited as a barrieringbase, was stacked; it was further sealed with a lid member formed bystacking a biaxially oriented polyethylene terephthalate film of 12 μmin thickness as the base film to fabricate a sealed packaged product.Next, the sealed packaged product was put into a retort boiler toundergo retort processing (sterilization with heat) under retortingconditions of 120° C. in temperature, 2.1 Kgf/cm²in pressure and 30minutes in duration to fabricate a packaged product having gone throughretort processing. The packaged product having gone through retortprocessing manifested no deformation of the container body or any otherdetect, and was found excelling in packaging suitability, retortingsuitability, distribution suitability, preservative suitability andother respects. The packaging container constituting this packagedproduct was not destroyed when it was dropped five times from a heightof 50 cm, and found excelling in oxygen permeability and humiditypermeability among other properties. The curry roux which was heated fortwo minutes in a 500 W microwave oven after the lid material of thepackaged product was peeled off became just hot enough to eat, sufferingno deformation of the container or any other trouble. Incidentally, inthe injection molded container, T1 (Ta) was 0.95 mm, T1, 1.0 mm, T2, 1.1mm, T3, 1.2 mm, and r1, 0.5 mm.

Example 4

By using a similar container to what was used in Embodiment 3, thecontainer was filled with 310 cc of tomato paste as its content, andsealed with the lid member over the opening. This container wassubjected to boiling sterilization at 95° C. for 60 minutes to provide aboil-treated package product. This boil-treated package productmanifested no deformation of the container body or any other detect, andwas found excelling in packaging suitability, retorting suitability,distribution suitability, preservative suitability and other respects.The packaging container constituting this packaged product was notdestroyed when it was dropped five times from a height of 50 cm, andfound excelling in oxygen permeability and humidity permeability amongother properties. The tomato paste which was heated for one minute in a500 W microwave oven after the lid material of the packaged product waspeeled off became just hot enough to eat, suffering no deformation ofthe container,or any other trouble, and the container was thus foundalso excellent for use involving boiling.

1. An inmold labeled type plastic container fabricated by an inmoldlabeling type fabricating method by which molding of the container andlabeling are accomplished at the same time by fitting an inmold labelinto a gap, and injecting molten resin into said gap, said gap beingformed by using a female metal mold and a male metal mold and by joiningsaid female mold and male mold, the inmold labeled type plasticcontainer being characterized in that a flange part is formed at theupper end of the side part of the container and with dimensions of 2 mmor more in flange width and 0.5 mm or more in flange thickness.
 2. Aninmold labeled type plastic container fabricated by an inmold labelingtype fabricating method by which molding of the container and labelingare accomplished at the same time by fitting an inmold label into a gap,and injecting molten resin into said gap, said gap being formed by usinga female metal mold and a male metal mold and by joining said femalemold and male mold, the inmold labeled type plastic container beingcharacterized in that a bottom rim is formed in the bottom part of thecontainer, with a dimension of not less than 0.3 mm but not more than 20mm, and the bottom rim is labeled in a similar way to the side part ofthe container.
 3. An inmold labeled type plastic container fabricated byan inmold labeling type fabricating method by which molding of thecontainer and labeling are accomplished at the same time by fitting aninmold label into a gap, and injecting molten resin into said gap, saidgap being formed by using a female metal mold and a male metal mold andby joining said female mold and male mold, the inmold labeled typeplastic container being characterized in that a flange part is formed atthe upper end of the side part of the container, with dimensions of 2 mmor more in flange width and 0.5 mm or more in flange thickness, a bottomrim is formed in the bottom part of the container, with a dimension ofnot less than 0.3 mm but not more than 20 mm, and the bottom rim islabeled in a similar way to the side part of the container.
 4. Theinmold labeled type plastic container according to claim 2 or claim 3,wherein the relationships among the wall thickness (A) of theintersection between said bottom rim and the bottom part of thecontainer, the wall thickness (B) of the bottom part of the containerand the wall thickness (C) of the side part of the container are:A≦2×B andA≦2×C.
 5. The inmold labeled type plastic container, according to one ofclaims 1-3, wherein the container is fabricated by using said femalemetal mold and male metal mold which are a female metal mold and a malemetal mold were joined at the flange part in the formed container, andso designed that the flange width of a flange part formed by the femalemold is smaller than the flange width of a flange part formed by themale mold.
 6. The inmold labeled type plastic container according to oneof claims 1-3, wherein the thickness of said label is not more than 150μm.
 7. The inmold labeled type plastic container according to one ofclaims 1-3, wherein the label is a label having a configuration in whicha plurality of thin films are stacked, the thin film positioned on thefront face and the thin film positioned on the rear face consist of thinfilms of the same material, and further at least a resin film layer anda barrier layer having a defined strength or barrier layers having adefined strength are stacked between these thin films.
 8. The inmoldlabeled type plastic container according to claim 7, wherein the thinfilm positioned on the front face and the thin film positioned on therear face of said label consist of biaxially oriented polypropyleneresin film layers or polyethylene resin film layers, said resin filmlayers having a defined strength consist of biaxially orientedpolyethylene terephthalate film layers, biaxially oriented polyamidefilm layers or biaxially oriented polypropylene film layers, and thebarrier layers consist of metal foil layers, vapor-deposited metal filmlayers or inorganic vapor-deposited oxide film layers.
 9. The inmoldlabeled type plastic container according to one of claims 1 to 3,wherein the relationship between the fluid length (L) of the injectedmolten resin and the average wall thickness (t) of the container is:L/t≦250.